Lather producing machine

ABSTRACT

A lather producing machine consisting of a body member having a liquid soap reservoir and a reservoir for gas under pressure therein, and a nozzle for the discharge of lather connected with said liquid soap reservoir, the pressure of said gas being responsive to the opening of a discharge valve at said nozzle, to bubble gas through a portion of said liquid soap to form coarse bubbles therein, and to force said bubbles through very small orifices in a lather generator to reduce the size thereof to the very small size required for rich lather, and to discharge said lather through said nozzle, said gas pressure being the sole operative force. An electric heater may be provided when it is desired that the finished lather be hot.

nited States atent 1 1 Snider, Jr. et al.

154] LATHER PRODUCING MACHINE [76] Inventors: John H. Snider, J12, Box 363, Route 2'; Harold H. Snider, Box 101, Route 2, both of Osceola, M01 64776 221 Filed: April26, 1971 211 Appl.No.: 137,251

[52] US. Cl ..222/67, 175/359.5, 222/146 HA,

222/190, 239/343 [5 1] Int. Cl. ..B67d 5/08 [58] Field of Search.222/l46 HA, 146 HE, 190, 195, 222/394, 67, 399; 239/343; 252/3595, 261/DlG. 26, 76, 77, 78; 259/D1G. 36

[56] References Cited UNITED STATES PATENTS 1 Jan. 23, 1973 Roust ..2's2/359.5 x Pacitti ..222/l46 HA [57] ABSTRACT A lather producing machine consisting of a body member having a liquid soap reservoir and a reservoir for gas under pressure therein, and a nozzle for the discharge of lather connected with said liquid soap reservoir, the pressure of said gas being responsive to the opening of a discharge valve at said nozzle, to bubble gas through a portion of said liquid soap to form coarse bubbles therein, and to force said bubbles through very small orifices in a lather generator to reduce the size thereof to the very small size required for rich lather, and to discharge said lather through 2,871,058 1/1959 Puglia ..222/146 HA x Said nozzle, Said gas Pressure being the Sole Operative 1,554,146 9/1925 Wager ..252/359.5 force. An electric heater may be provided when it is 1,995,215 3/1935 Mehlsen et a1. ..239/343 X desired that the finished lather be hot. 3,388,868 6/1968 Watson et al ....239/343 X 2,221,487 11/1940 Moore.; ..222/67 5 Claims, 1 Drawing Figure 425 02? a; 49 Q4 4 v r. v s m 82 a 64 I) M g //5 1 u 74 J2 WW //2 w flag; 7; .92 If 7 i will 1 l4 )0 21 M0 95 74' 3b 96 /5 7 l 42 r 4' I a l 1 F 1 :7!- I 5' I l I -A- "4 l v T 17 w h 1 J A a m /1 LATHER PRODUCING MACHINE This invention relates to new and useful improvements in lather producing machines, and has particular reference to a machine adapted to produce a smooth, rich lather from a liquid soap, such as a shaving lather or toilet soap lather. As such, the machine is particularly suited for use in barber shops, public rest rooms and the like, but it will be apparent that the machine is also well suited for home use, or for producing foams or lathers for other purposes.

The principal object of the present invention is the provision of a lather producing machine having a novel means for converting liquid soap into lather, by means of which a gas is first bubbled through the liquid soap to form relatively large, coarse bubbles in conjunction therewith, and said bubbles then forced through a lather generator consisting of two or more perforated plates arranged in order of decreasing perforation size, whereby the original large coarse bubbles are reduced in steps to the very small, fine size required for a rich smooth lather.

Another object is the provision of a lather producing machine of the character described wherein a source of gas under pressure serves as the sole operating power for the machine, serving both to bubble the gas through the liquid soap and to drive the resulting bubbles through the lather generator.

A further object is the provision of a lather producing machine of the character described wherein the gas source constitutes a commercially available can or container of liquified gas held in liquid form by gasification of a portion thereof to produce an equilibrium pressure above the liquid level therein. As will appear, this provides a large volume of gas in a small container, for greater economy of size and operation, and still more importantly providesautomatic pressure regulation for the entire system.

A still further object is the provision of a lather producing machine of the character described having heater means for heating the lather whenever a hot lather may be desired. Said heater requires outside electric power, but operates only while lather is being delivered.

Other objectsare simplicity and economy of construction, and efficiency anddependability of operation.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the accompanying drawing, wherein the single view is a partially schematic vertical sectional view of a lather producing machine embodying the present invention.

in said drawing, the numeral 2 applies generally to a housing base or body member formed of any suitable structural material, divided by a partition wall 4 into a reservoir 6 for containing liquid soap 8, and a well 10 for containing a gas can 12 to be described. Well 10 opens upwardly, while reservoir, 6 is closed and sealed at its top by a top wall 14, the sealing connection being indicated at 16. The top wall is provided with a filling opening 18 through which liquid soap may be pouredinto the reservoir, and said opening is provided with a screw closure cap 20, said cap having a sealing ring 22 whereby the reservoir may be maintained pressurized.

Formed integrally with top wall l4, and depending therefrom into soap reservoir 6, is a cylindrical wall 24 defining therein a bubble chamber 26. Wall 24 terminates in closely spaced relation from the bottom of chamber 6, and is closed at its lower end by a horizontal valve plate 28 in which is formed a valve seat 30 interconnecting reservoir 6 and bubble chamber 26. Said valve seat is controlled by a tapered valve member 32 affixed to a vertical stem 34 slidable in a guide 36 formed by valve plate 28, and secured at its upper end to a sealed, buoyant float 38 disposed within the bubble chamber. Thus whenever the liquid level 40 of soap in the bubble chamber rises to the level shown, the buoyancy of the float causes it to close valve 32, while any lower liquid level will cause said valve to open.

Also formed integrally with top wall 14 and depending therefrom within bubble chamber 26, is a cylindrical wall 42 defining therein a lather generator chamber 44. Mounted in chamber 44 are a plurality (two shown) of horizontal, vertically spaced apart perforated plates 46 and 48 having very small holes 50 formed vertically therethrough. The holes of the lower plate are larger than those of the upper plate, the holes of the upper plate corresponding to the diameter of the bubbles desired in the finished lather. The upper plate has more holes than the lower plate, in order that the capacity of the two plates for passing the soap-gas mixture is maintained about equal.

Opening from the top of lather generator chamber 44 is a passage 52 formed in top wall 14 and communicating with a valve body 54 sealed in said top wall. Entrance to said valve body is controlled by a tapered valve 56 having a vertical stem 58 extending slidably upwardly through said valve body to a point above said valve body, and provided at its upper end with an enlarged head 60. A compression spring 62 interposed between the valve body and head 60 biases valve 56 closed, but it may be opened by pressing downwardly on head 60. A lever 64 pivoted at 66 toa fixed standard 68 carried by top wall 14 rests intermediate its ends on head 60, and extends outwardly from one side of base 2. Just above valve 56, valve body 54 opens into a passageway 70 formed in top wall 14 and communicating with a nozzle 72 secured to top wall 14 by screws 74, and also extending outwardly from one side of base 2, preferably just beneath the outer end of lever 64. If hot lather is desired, a portion of the nozzle is surrounded by a quick-acting electric heater 76 to which electric current is furnished by wires 78 and 80 from line wires 82 and 84. Interposed in wire 78 is a normally-open switch 86 controlled by an operating member 88 disposed adjacent lever 64, whereby said switch is closed whenever said lever is depressed to open valve 56. When heating of the lather is not deemed necessary, a nozzle without the heater-switch combination described may be substituted for that shown, the detachability of the nozzle provided by screws 74 facilitating this change.

Gas can 12 may be of a common, well known commercially available type, containing a gas which is liquified and maintained in liquid form by pressure created above the liquid level therein by transfer of a portion thereof into gaseous or vapor form. When this pressure reaches a certain level, designated the equilibrium pressure it will maintain the rest of the material in liquid form. Each time the pressure in the can is allowed to drop by allowing gas to escape, more 3 of the liquid will pass into gaseous form until the equiibrium pressure is again restored. The equilibrium pressure varies with the temperature of the liquid, but remains substantially constant for any given temperature. For use in the present machine, a liquid gas is selected having equilibrium pressures, at all ambient temperatures to which can 12 is likely to be subjected, within a range suitable for operating the bubbling and lather generating elements of the machine, say l-30 p.s.i. The gas should of course also be completely nontoxic and non-inflammable, and preferably substantially odorless. Certain grades of a liquid refrigerant gas commonly known as Freon meet all of these requirements, although other liquid flourinated hydrocarbons could be used. Even pressurized air functions satisfactorily, but the use of air would require a huge container as compared to can 12 to eject the same volume of gas, and would also require an expensive regulator valve to maintain the desired pressure in the lather forming steps, while the liquid gases, by their tendency to seek a fixed equilibrium pressure, provide automatic pressure regulation. Also, as will appear,.the use of liquid gases somewhat improves the quality of the lather produced.

Commercially available gas cans such as illustrated at 12 are ordinarily furnished with a cap 90 equipped with a valve, not shown but common and well known in the art, controlled by an upwardly projecting hollow valve stem 92, in such manner that gas is ejected upwardly through said stem whenever said stem is pressed downwardly or tilted laterally. For purposes of the present machine, there is provided a cover 94 having flexible teeth 96 adapted to snap over the cap 90 of the can, whereby to secure said cover in place with valve stem 92 enclosed therein-The cover'is provided'with a sealing ring 98 to prevent leakage of gas between said cover and said cap. Said cover is provided with an internal cam 100 which is operable, whenever said cap is applied to the can as just described, to tilt valve stem 92 laterally to one side, as shown, whereby to allow gas to escape from the can. The cover is provided with a top outlet neck 102, whichis interconnected by a flexible hose 1 04 to acheck valve fitting 106 screwed into a passage 108, formed in topwall'14. A weak spring 110 in passage vltl8biases a check valve 112, carried soap is poured, it also enters bubble chamber 26 through valve 32 (open at that time) rising in said chamber until it reaches the level 40 shown, at which time float .38 closes valve 32. Reservoir 6, however, may be filled to a higher level as indicated at 126. Level must be substantially higher than perforated cap 120 of tube 118, but well below the lower end of generator chamber 44. Cover 94 is then snapped over can cap 90 as described, thus tilting valve stem 92 of the can laterally as shown, allowing gas to escape from the can and flow through hose 104, check valve 112 and passages 108 and 114 to reservoir 6 above soap level 126 therein, and from passageway 108 and perforated cap 120 into bubble chamber 26 beneath the soap level therein. This gas bubbles upwardly through the liquid soap in said chamber to pressurize said chamber above the liquid level therein. Thus, the entire system up to valve 56 (then closed), including reservoir 6, bubble chamber 26, and generator chamber 44, is pressurized at the equilibrium pressure of the liquid gas in can 12. At this time bubbles will form in chamber 26 above the liquid level, due to the bubbling of gas through the liquid soap therein, but these bubbles quickly subside when equilibrium pressure is reached and the bubbling of the gas is halted.

Whenever lather is desired, the user depresses lever 64 to open valve 56, preferably doing so with his thumb while holding his palm or fingers under nozzle 72 to catch the lather discharged therefrom. The opening of valve 56 allows the escape of gas to the nozzle, and reduces gas pressure in bubble chamber 26 and generator chamber 44. Only gas escapes from nozzle 72 during the first few instants after valve 56 is opened. However, the reduction of pressure in chamber 26 immediately. allows gas, under direct pressure from can 12, to emerge through perforations 122 ofcap 120 at the lower end of bubble tube 118. This gas bubbles upwardlythrough the liquid soap in chamber 26, almost immediately filling the entirevolume of said chamber above the liquid level thereinwith soap bubbles. These bubbles are too large to constitute lather, but are then forced by the pressure through the perforations of reduced sufficiently to impart a rich, smooth lather texture to the mixture. The lather is thenforced throughslidably in said passage, into closed relationship with a valve seat formed in fitting 106, wherebyto prevent gas from flowing toward can 12, while at the same time permitting gas flow from the can. Passageway 108, at points behind valve 112, is connected by passages 114 and l l6, also formed in top wall 14, respectively to the top of soap reservoir 6, and to the upper end of a small vertical bubble tube 118. Said bubble tube is fixed at its upper end .in top wall 14, and extends downwardly through bubble chamber 26 to a point adjacent the bottom thereof, being fitted at its lower end with a cupshaped cap 120- having small perforations 122 formed therein and opening intochamber 26. For neatness and eye appeal, the entire top of body 2, including top plate 14, well 10, the gas can, and all mechanism carried by said top plate, may be concealed by a removable cover 124, with only lever 64 and spout 72 extending outwardly from said cover.

To set the machine in operation, reservoir cap 20 is first removed and liquid soap 8poured into reservoir 6 before can cover 94 is engaged over can cap 90. As the generator plates 46 and 48, whereby the bubble size is valve 56 and nozzle 72 to be discharged therefrom, being heated in the nozzle if desired by heater 76, the operating switch 86 of which was closed by the depression of lever 64. Said heater is of course selected to heat the lather to the desired temperature in the short time available. The flow of lather of course continues as long as valve 56 is held open and terminates when lever 64 is released and said valve closes.

The bubbling and generator action should be more fully described. First, it should be appreciated that the mere bubbling of gas from cap through the liquid soap cannot produce bubbles small enough to be considered a lather. While the bubble size in chamber 26 can be reduced somewhat by reducing the size of perforations 122 in cap 120, and while said perforations are made very small for this reason, the size of the bubbles in chamber 26 is apparently dictated primarily by the viscosity of the liquid soap itself, not the size of perlather in any accepted general meaning of that term, and in fact are not capable of holding their form for any substantial length of time, subsiding rapidly to liquid form. Thus the action of the generator is necessary.

The action of either of generator plates 46 and 48 is that any bubble, which of course is a quantity of gas surrounded by a liquid soap film of high surface tension, approaches and passes through an orifice of said plate, it is of course reduced in diameter to the diameter of the orifice. Furthermore, as it passes through the orifice, it tends to break up longitudinally of the orifice into smaller bubbles, since any bubble due to its surface tension, assumes as nearly a spherical shape as possible. Thus the soap film divides into a series of films moving upwardly through the orifice in ladder-like spacing, the distance between adjacent films tending to equal the diameter of the orifice, this being the nearest the bubbles can approach spherical shape. When the smaller bubbles emerge from the upper end of the orifice, they tend to assume spherical shapes of diameters generally equal to the diameter of the orifice in which they were formed. To give the ladder" of films the space in which to form in each orifice, it is necessary that each generator plate be as thick as the diameter of the orifices therein, and preferably at least two or three times that thickness.

it has also been found that the bubbles in chamber 26 cannot ordinarily be reduced to lather size in a singlestage generator having only one perforated plate. This appears to be the result of the fact that if a bubble approaches an orifice proportionately smaller in too great a degree than the diameter of the bubble itself, and the bubble film breaks to allow its gas to enter the orifice, said gas may blow through the orifice so rapidly that the ladder of films does not have the time necessary for it to form. As a result, the bubbles emerging at the discharge side of the plate might be only slightly reduced in size, if at all. It is for this reason that the present device utilizes two generator plates 46 and 48, the second or last plate (46) through which the bubbles pass having smaller orifices than the first plate (48) through which the bubbles pass, though plate 46 has more orifices than plate 48 to preserve an equal flow capacity. I

Thus the bubble size of the finished latheris determined by the size of the orifices in plate 46. A lather suitably fine-grained for most purposes hasbeen found to be produced if these orifices are about 0.016 inch in diameter, but could be still further refined by the use of one or more additional plates disposed above plate 46, with orifices of progressively smaller diameter, if desired. With the orifices of plate 46 of the size given, the orifices of plate 48 may be about 0.020 inch in diameter, and orifices 1122 of cap 120 about 0.005 inch in diameter (holes still smaller having been found to produce bubbles of no appreciably smaller size in chamber 26), with liquid soap of common viscosity and with an equilibrium pressure of about p.s.i. in gas can 12. However, all of these specific figures are exemplary only, and would necessarily be varied in each application depending on such factors as operating pressure, soap viscosity, fineness of lather desired, and the specific design of the apparatus.

As previously mentioned, the liquid level 40 in bubble chamber 26 must be maintained above bubble cap 120, to give the bubbles formed by gas escaping from said cap time form and disperse through the liquid, and below generator chamber 44, since if it rose to said generator, nozzle 72 would dispense liquid soap, not lather. Float valve 32 provides this level control. if reservoir level 126 is above level 40, soap will flow from the reservoir to chamber 26 through valve 32 by gravity whenever level 40 drops slightly to allow float 38 to open said valve, and as long as the pressure in the reservoir and chamber 26 is equal, which is the normal rest condition of the system. The flow to chamber 26 will continue until level 40 is restored, whereupon float 38 will close valve 32. When reservoir level 126 drops below level 40, then refill of chamber 26 to level 40 is accomplished whenever lever 64 is depressed to discharge lather. At that time, pressure in chamber 26 drops as already described, while the pressure in reservoir 6 does not drop, or drops only to a lesser degree. The resultant higher pressure over the soap in the reservoir then forces soap through valve 32 to restore level 40 therein, if there has been a drop in level 40 due to use of soap therefrom, and float 38 has thus allowed valve 32 to open. Actually the rise and fall of level 40 is virtually never so large as to be perceptible to the eye, but the soap in reservoir 6 may be used until its level drops to the bottom of the bubble chamber.

Can 12 may be replaced at any time with a new one, when its contents are exhausted, by removing cover 94 therefrom, removing the old can and replacing it with a new one, and applying cover 94 to the new one. At this time, check valve 112 obviates any necessity of depressurizing the reservoir, bubble, and generator chambers, and thus prevents wastage of the gas. Replenishment of reservoir 6 with liquid soap of course requires removal of filler cap 20, and this of course de-pressurizes the entire system. Whenever the filler cap is removed, cover 94 should be removed from can 12 to further prevent wastage of gas. In anticipated proportions, reservoir 6 will contain enough soap for hundreds or perhaps thousands of normal lather applications, and can 12 will contain enough gas to dispense several fillings of the reservoir.

It has been previously mentioned that the use of a gas capable of liquifying at the pressures involved in the system has a beneficialeffect on the lathering action. This effect arises from the fact'that the pressurized in chamber 26 over liquid level 40, being under the same equilibrium pressure which maintains gas in liquid form in can 12, tends to return to liquid form and mix with the surface layers of the liquid soap in said chamber. Then, when pressure in chamber 26 is reduced by the opening of valve 56, the liquid gas therein passes instantly into gaseous or vapor form, producing myriads of small bubbles which in nearly all cases are smaller than those produced by bubble cap 120, and may in some cases be even smaller than the orifices of generator plate 46, and pass through said orifices freely and without enlargement. Since the lather texture and fineness is improved by a smaller bubble size, this expansive bubbling improves the quality of the lather. However, at least in the absence of agitation, the gas liquifies only in the extreme surface layers of the liquid soap, so that the lather improvement from this cause is only slight, and temporary. Actually, even compressed air, which of course will not liquify in the liquid soap at any normal pressure, will produce quite acceptable lather in the present machine, and the reasons for the use of an aerosol gas are those already stated, that is, large capacity in a small container, and automatic pressure regulation.

While we have shown and described a specific embodiment of our invention, it will be readily apparent that many minor. changes of structure and operation could be made without departing from the spirit of the invention.

What we claim as new and desire to protect by Letters Patent is:

1, A lather producing machine comprising:

a. a body member including a bubble chamber adapted to contain liquid soap up to a predetermined level,

b. a source of gas under pressure,

c. a conduit interconnecting said gas source with said bubble chamber and operable to discharge gas into said chamber beneath the level of the liquid soap therein,

d. a lather generator chamber having an inlet opening into said bubble chamber above the soap level therein and an outlet opening exteriorly of said chamber,

e. at least one generator ,plate obstructing said generator chamber intermediate its inlet and outlet and having small orifices formed therethrough,

f. a discharge nozzle interconnected with the outlet of said generator chamber,

g. a normally closed, manually operable discharge valve operable to control the flow of gas from said gas source, whereby when said discharge valve is opened, gas is bubbled upwardly through the liquid soap in said bubble chamber and gas-soap bubbles collect on the liquid surface in said chamber and rise to the elevation of the inlet of said generator chamber, and are thence forced through the orificesof said generator plate to said discharge nozzle in lather form, the diameters of said generator plate orifices being smaller than the liquid gas vaporizes only when said discharge valve is diameters of the bubbles produced in said bubble chamber whereby the diameter of said bubbles are reduced by their passage through sa id generator Plate, w I t h. a liquid soap reservoir in said body member exteriorly of said bubble chamber, and interconnected with said bubble chamber, said reservoir being adapted to contain liquid soap at levels both above and below the predetermined soap level in said bubble chamber, and I i. delivery means operable to deliver liquid soap from said reservoir to said bubble chamber, and automatically to maintain the liquid soap in said chamber at said predetermined level regardless of the levelof the liquid soap in said reservoir.

o ened and onl so ion as ma egtablish said eqti ilibrium pressur e valve is closed.

3. A lather producing machine as recited in claim 1 with the addition of:

a. a heater element operable, when actuated, to heat lather as it flows from said generator chamber to said discharge nozzle, and

b. a manually movable operating member carried by said body member, and operable to open said discharge valve and actuate said heater element substantially simultaneously.

4. A lather producing machine as recited in claim 1 wherein said delivery means comprises:

a. a valve disposed in the interconnection between said reservoir and said bubble chamber, adjacent the bottom of each, I

. a buoyant float disposed in said bubble chamber and movable responsively to the liquid level therein,

. means connecting said float and said valve whereby said valve is closed whenever the liquid soap in said chamber rises to said predetermined level, and opened whenever said liquid soap drops to any lower level, whereby so long as the liquid level of said reservoir is higher than that of said bubble chamber, liquid soap will flow through said valve to said chamber whenever said valve is open,

. means connecting said gas source to said reservoir above the liquid level thereof, and means sealing said reservoir, whereby liquid soap will be forced through said float valve to said bubble chamber whenever said float valve is open, and so long as the gas pressure in said bubble chamber is lower than that in said reservoir, whereby the liquid soap from said reservoir will continue to flow to said bubble chamber when the liquid level of the fromer drops below that of the latter,

5. A lather producing machine as recited in claim 4 wherein said discharge valve is disposed intermediate said generator chamber and said discharge nozzle and said gas source is connected directly to both said reservoir and said bubble chamber, whereby the reservoir and chamber are normally equally pressurized, opening of said discharge valve thereby'se'rving to reduce the pressure of said bubble chamber below that of said reservoir.

be. necessary to reafter said discharge are 

1. A lather producing machine comprising: a. a body member including a bubble chamber adapted to contain liquid soap up to a predetermined level, b. a source of gas under pressure, c. a conduit interconnecting said gas source with said bubble chamber and operable to discharge gas into said chamber beneath the level of the liquid soap therein, d. a lather generator chamber having an inlet opening into said bubble chamber above the soap level therein and an outlet opening exteriorly of said chamber, e. at least one generator plate obstructing said generator chamber intermediate its inlet and outlet and having small orifices formed therethrough, f. a discharge nozzle interconnected with the outlet of said generator chamber, g. a normally closed, manually operable discharge valve operable to control the flow of gas from said gas source, whereby when said discharge valve is opened, gas is bubbled upwardly through the liquid soap in said bubble chamber and gas-soap bubbles collect on the liquid surface in said chamber and rise to the elevation of the inlet of said generator chamber, and are thence forced through the orifices of said generator plate to said discharge nozzle in lather form, the diameters of said generator plate orifices being smaller than the diameters of the bubbles produced in said bubble chamber whereby the diameter of said bubbles are reduced by their passage through said generator plate, h. a liquid soap reservoir in said body member exteriorly of said bubble chamber, and interconnected with said bubble chamber, said reservoir being adapted to contain liquid soap at levels both above and below the predetermined soap level in said bubble chamber, and i. delivery means operable to deliver liquid soap from said reservoir to said bubble chamber, and automatically to maintain the liquid soap in said chamber at said predetermined level regardless of the level of the liquid soap in said reservoir.
 2. A lather producing machine as recited in claim 1 wherein said gas source comprises a container carried removably by said body member and containing a liquid gas capable, at normal temperatures, of being retained in liquid form by above-atmospheric equilibrium pressure generated by vaporization of a portion thereof above the liquid level therein, whereby said liquid gas vaporizes only when said discharge valve is opened, and only so long as may be necessary to re-establish said equilibrium pressure after said discharge valve is closed.
 3. A lather producing machine as recited in claim 1 with the addition of: a. a heater element operable, when actuated, to heat lather as it flows from said generator chamber to said discharge nozzle, and b. a manually movable operating member carried by said body member, and operable to open said discharge valve and actuate said heater element substantially simultaneously.
 4. A lather producing machine as recited in claim 1 wherein said delivery means comprises: a. a valve disposed in the interconnection between said reservoir and said bubble chamber, adjacent the bottom of each, b. a buoyant float disposed in said bubble chamber and movable responsively to the liquid level therein, c. means connecting said float and said valve whereby said valve is closed whenever the liquid soap in said chamber rises to said predetermined level, and opened whenever said liquid soap drops to any lower level, whereby so long as the liquid level of said reservoir is higher than that of said bubble chamber, liquid soap will flow through said valve to said chamber whenever said valve is open, d. means connecting said gas source to said reservoir above the liquid level thereof, and means sealing said reservoir, whereby liquid soap will be forced through said float valve to said bubble chamber whenever said float valve is open, and so long as the gas pressure in said bubble chamber is lower than that in said reservoir, whereby the liquid soap from said reservoir will continue to flow to said bubble chamber when the liquid level of the fromer drops below that of the latter.
 5. A lather producing machine as recited in claim 4 wherein said discharge valve is disposed intermediate said generator chamber and said discharge nozzle and said gas source is connected directly to both said reservoir and said bubble chamber, whereby the reservoir and chamber are normally equally pressurized, opening of said discharge valve thereby serving to reduce the pressure of said bubble chamber below that of said reservoir. 